Targeting enhancer switching overcomes non-genetic drug resistance in acute myeloid leukaemia [ATAC-seq]
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE110900 | GEO | 2019/05/21
REPOSITORIES: GEO
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Project description:The prevailing model of therapeutic resistance in cancer posits that malignant cells acquire genetic mutations in the context of therapeutic pressure that negate the efficacy of the drug. This mutation centric view of therapeutic resistance has recently been challenged by emerging evidence that shows a paucity of genetic diversity in malignant cells that evade therapeutic challenge emphasizing the role of epigenetic evolution in drug resistance. We have previously established that therapeutic resistance emerges in the absence of genetic adaptation from leukemia stem cells and whilst the clinical relevance of these findings has been established, what remains unanswered is whether transcriptional programs that confer resistance to therapies are pre-existing or acquired. It is also unclear how stable this adaptive transcriptional response is and whether it can be reversed. Here, we utilize a unique leukaemia model to highlight the key principles of epigenetic resistance. Using single cell RNA-seq with indexed flow sorting, we demonstrate that a form of Lamarckian evolution, namely transcriptional plasticity, drives epigenetic resistance. With a CRISPR-Cas9 screen we identify reciprocal regulators of the enhancer modification H3K4me1/2, LSD1 and MLL4, as important modulators of the resistant cell state. Knockdown or catalytic inhibition of LSD1 causes reversion to a drug sensitive state that is dependent on the lineage determining pioneer transcription factor Pu.1. Mechanistically, we establish that inhibition of LSD1 results in newly formed enhancers marked by H3K4me1/2, H3K27ac and Pu.1 binding, which facilitates the recruitment of transcriptional co-activators and activation of a differentiation gene expression program. We show that this enhancer-remodeling does not result in a simple linear reversion to the original chromatin state of drug naive cells, rather it reinstates the cells dependence on transcriptional co-activators including Med1 and Brd4 due to the formation of new enhancers with enhancer-promoter loops to canonical Brd4 target genes. Together these findings provide new insights into the molecular mechanisms that facilitate epigenetic resistance to cancer therapies and highlight new opportunities for therapeutic intervention to overcome transcriptional plasticity.
2019-05-21 | GSE122843 | GEO
Project description:The prevailing model of therapeutic resistance in cancer posits that malignant cells acquire genetic mutations in the context of therapeutic pressure that negate the efficacy of the drug. This mutation centric view of therapeutic resistance has recently been challenged by emerging evidence that shows a paucity of genetic diversity in malignant cells that evade therapeutic challenge emphasizing the role of epigenetic evolution in drug resistance. We have previously established that therapeutic resistance emerges in the absence of genetic adaptation from leukemia stem cells and whilst the clinical relevance of these findings has been established, what remains unanswered is whether transcriptional programs that confer resistance to therapies are pre-existing or acquired. It is also unclear how stable this adaptive transcriptional response is and whether it can be reversed. Here, we utilize a unique leukaemia model to highlight the key principles of epigenetic resistance. Using single cell RNA-seq with indexed flow sorting, we demonstrate that a form of Lamarckian evolution, namely transcriptional plasticity, drives epigenetic resistance. With a CRISPR-Cas9 screen we identify reciprocal regulators of the enhancer modification H3K4me1/2, LSD1 and MLL4, as important modulators of the resistant cell state. Knockdown or catalytic inhibition of LSD1 causes reversion to a drug sensitive state that is dependent on the lineage determining pioneer transcription factor Pu.1. Mechanistically, we establish that inhibition of LSD1 results in newly formed enhancers marked by H3K4me1/2, H3K27ac and Pu.1 binding, which facilitates the recruitment of transcriptional co-activators and activation of a differentiation gene expression program. We show that this enhancer-remodeling does not result in a simple linear reversion to the original chromatin state of drug naive cells, rather it reinstates the cells dependence on transcriptional co-activators including Med1 and Brd4 due to the formation of new enhancers with enhancer-promoter loops to canonical Brd4 target genes. Together these findings provide new insights into the molecular mechanisms that facilitate epigenetic resistance to cancer therapies and highlight new opportunities for therapeutic intervention to overcome transcriptional plasticity.
2019-05-21 | GSE110897 | GEO
Project description:The prevailing model of therapeutic resistance in cancer posits that malignant cells acquire genetic mutations in the context of therapeutic pressure that negate the efficacy of the drug. This mutation centric view of therapeutic resistance has recently been challenged by emerging evidence that shows a paucity of genetic diversity in malignant cells that evade therapeutic challenge emphasizing the role of epigenetic evolution in drug resistance. We have previously established that therapeutic resistance emerges in the absence of genetic adaptation from leukemia stem cells and whilst the clinical relevance of these findings has been established, what remains unanswered is whether transcriptional programs that confer resistance to therapies are pre-existing or acquired. It is also unclear how stable this adaptive transcriptional response is and whether it can be reversed. Here, we utilize a unique leukaemia model to highlight the key principles of epigenetic resistance. Using single cell RNA-seq with indexed flow sorting, we demonstrate that a form of Lamarckian evolution, namely transcriptional plasticity, drives epigenetic resistance. With a CRISPR-Cas9 screen we identify reciprocal regulators of the enhancer modification H3K4me1/2, LSD1 and MLL4, as important modulators of the resistant cell state. Knockdown or catalytic inhibition of LSD1 causes reversion to a drug sensitive state that is dependent on the lineage determining pioneer transcription factor Pu.1. Mechanistically, we establish that inhibition of LSD1 results in newly formed enhancers marked by H3K4me1/2, H3K27ac and Pu.1 binding, which facilitates the recruitment of transcriptional co-activators and activation of a differentiation gene expression program. We show that this enhancer-remodeling does not result in a simple linear reversion to the original chromatin state of drug naive cells, rather it reinstates the cells dependence on transcriptional co-activators including Med1 and Brd4 due to the formation of new enhancers with enhancer-promoter loops to canonical Brd4 target genes. Together these findings provide new insights into the molecular mechanisms that facilitate epigenetic resistance to cancer therapies and highlight new opportunities for therapeutic intervention to overcome transcriptional plasticity.
2019-05-21 | GSE110894 | GEO
Project description:The prevailing model of therapeutic resistance in cancer posits that malignant cells acquire genetic mutations in the context of therapeutic pressure that negate the efficacy of the drug. This mutation centric view of therapeutic resistance has recently been challenged by emerging evidence that shows a paucity of genetic diversity in malignant cells that evade therapeutic challenge emphasizing the role of epigenetic evolution in drug resistance. We have previously established that therapeutic resistance emerges in the absence of genetic adaptation from leukemia stem cells and whilst the clinical relevance of these findings has been established, what remains unanswered is whether transcriptional programs that confer resistance to therapies are pre-existing or acquired. It is also unclear how stable this adaptive transcriptional response is and whether it can be reversed. Here, we utilize a unique leukaemia model to highlight the key principles of epigenetic resistance. Using single cell RNA-seq with indexed flow sorting, we demonstrate that a form of Lamarckian evolution, namely transcriptional plasticity, drives epigenetic resistance. With a CRISPR-Cas9 screen we identify reciprocal regulators of the enhancer modification H3K4me1/2, LSD1 and MLL4, as important modulators of the resistant cell state. Knockdown or catalytic inhibition of LSD1 causes reversion to a drug sensitive state that is dependent on the lineage determining pioneer transcription factor Pu.1. Mechanistically, we establish that inhibition of LSD1 results in newly formed enhancers marked by H3K4me1/2, H3K27ac and Pu.1 binding, which facilitates the recruitment of transcriptional co-activators and activation of a differentiation gene expression program. We show that this enhancer-remodeling does not result in a simple linear reversion to the original chromatin state of drug naive cells, rather it reinstates the cells dependence on transcriptional co-activators including Med1 and Brd4 due to the formation of new enhancers with enhancer-promoter loops to canonical Brd4 target genes. Together these findings provide new insights into the molecular mechanisms that facilitate epigenetic resistance to cancer therapies and highlight new opportunities for therapeutic intervention to overcome transcriptional plasticity.
2019-05-21 | GSE110896 | GEO
Project description:The prevailing model of therapeutic resistance in cancer posits that malignant cells acquire genetic mutations in the context of therapeutic pressure that negate the efficacy of the drug. This mutation centric view of therapeutic resistance has recently been challenged by emerging evidence that shows a paucity of genetic diversity in malignant cells that evade therapeutic challenge emphasizing the role of epigenetic evolution in drug resistance. We have previously established that therapeutic resistance emerges in the absence of genetic adaptation from leukemia stem cells and whilst the clinical relevance of these findings has been established, what remains unanswered is whether transcriptional programs that confer resistance to therapies are pre-existing or acquired. It is also unclear how stable this adaptive transcriptional response is and whether it can be reversed. Here, we utilize a unique leukaemia model to highlight the key principles of epigenetic resistance. Using single cell RNA-seq with indexed flow sorting, we demonstrate that a form of Lamarckian evolution, namely transcriptional plasticity, drives epigenetic resistance. With a CRISPR-Cas9 screen we identify reciprocal regulators of the enhancer modification H3K4me1/2, LSD1 and MLL4, as important modulators of the resistant cell state. Knockdown or catalytic inhibition of LSD1 causes reversion to a drug sensitive state that is dependent on the lineage determining pioneer transcription factor Pu.1. Mechanistically, we establish that inhibition of LSD1 results in newly formed enhancers marked by H3K4me1/2, H3K27ac and Pu.1 binding, which facilitates the recruitment of transcriptional co-activators and activation of a differentiation gene expression program. We show that this enhancer-remodeling does not result in a simple linear reversion to the original chromatin state of drug naive cells, rather it reinstates the cells dependence on transcriptional co-activators including Med1 and Brd4 due to the formation of new enhancers with enhancer-promoter loops to canonical Brd4 target genes. Together these findings provide new insights into the molecular mechanisms that facilitate epigenetic resistance to cancer therapies and highlight new opportunities for therapeutic intervention to overcome transcriptional plasticity.
2019-05-21 | GSE110895 | GEO
Project description:The prevailing model of therapeutic resistance in cancer posits that malignant cells acquire genetic mutations in the context of therapeutic pressure that negate the efficacy of the drug. This mutation centric view of therapeutic resistance has recently been challenged by emerging evidence that shows a paucity of genetic diversity in malignant cells that evade therapeutic challenge emphasizing the role of epigenetic evolution in drug resistance. We have previously established that therapeutic resistance emerges in the absence of genetic adaptation from leukemia stem cells and whilst the clinical relevance of these findings has been established, what remains unanswered is whether transcriptional programs that confer resistance to therapies are pre-existing or acquired. It is also unclear how stable this adaptive transcriptional response is and whether it can be reversed. Here, we utilize a unique leukaemia model to highlight the key principles of epigenetic resistance. Using single cell RNA-seq with indexed flow sorting, we demonstrate that a form of Lamarckian evolution, namely transcriptional plasticity, drives epigenetic resistance. With a CRISPR-Cas9 screen we identify reciprocal regulators of the enhancer modification H3K4me1/2, LSD1 and MLL4, as important modulators of the resistant cell state. Knockdown or catalytic inhibition of LSD1 causes reversion to a drug sensitive state that is dependent on the lineage determining pioneer transcription factor Pu.1. Mechanistically, we establish that inhibition of LSD1 results in newly formed enhancers marked by H3K4me1/2, H3K27ac and Pu.1 binding, which facilitates the recruitment of transcriptional co-activators and activation of a differentiation gene expression program. We show that this enhancer-remodeling does not result in a simple linear reversion to the original chromatin state of drug naive cells, rather it reinstates the cells dependence on transcriptional co-activators including Med1 and Brd4 due to the formation of new enhancers with enhancer-promoter loops to canonical Brd4 target genes. Together these findings provide new insights into the molecular mechanisms that facilitate epigenetic resistance to cancer therapies and highlight new opportunities for therapeutic intervention to overcome transcriptional plasticity.
2019-05-21 | GSE110899 | GEO
Project description:The prevailing model of therapeutic resistance in cancer posits that malignant cells acquire genetic mutations in the context of therapeutic pressure that negate the efficacy of the drug. This mutation centric view of therapeutic resistance has recently been challenged by emerging evidence that shows a paucity of genetic diversity in malignant cells that evade therapeutic challenge emphasizing the role of epigenetic evolution in drug resistance. We have previously established that therapeutic resistance emerges in the absence of genetic adaptation from leukemia stem cells and whilst the clinical relevance of these findings has been established, what remains unanswered is whether transcriptional programs that confer resistance to therapies are pre-existing or acquired. It is also unclear how stable this adaptive transcriptional response is and whether it can be reversed. Here, we utilize a unique leukaemia model to highlight the key principles of epigenetic resistance. Using single cell RNA-seq with indexed flow sorting, we demonstrate that a form of Lamarckian evolution, namely transcriptional plasticity, drives epigenetic resistance. With a CRISPR-Cas9 screen we identify reciprocal regulators of the enhancer modification H3K4me1/2, LSD1 and MLL4, as important modulators of the resistant cell state. Knockdown or catalytic inhibition of LSD1 causes reversion to a drug sensitive state that is dependent on the lineage determining pioneer transcription factor Pu.1. Mechanistically, we establish that inhibition of LSD1 results in newly formed enhancers marked by H3K4me1/2, H3K27ac and Pu.1 binding, which facilitates the recruitment of transcriptional co-activators and activation of a differentiation gene expression program. We show that this enhancer-remodeling does not result in a simple linear reversion to the original chromatin state of drug naive cells, rather it reinstates the cells dependence on transcriptional co-activators including Med1 and Brd4 due to the formation of new enhancers with enhancer-promoter loops to canonical Brd4 target genes. Together these findings provide new insights into the molecular mechanisms that facilitate epigenetic resistance to cancer therapies and highlight new opportunities for therapeutic intervention to overcome transcriptional plasticity.
2019-05-21 | GSE110898 | GEO
Project description:Clinical responses to kinase inhibitor therapy in acute myeloid leukemia (AML) are limited by the inevitable development of resistance. A major contributor to resistance is early epigenetic adaptation, leading to persistence of a small number of leukemia cells. Here we show that inhibition of the epigenetic regulator lysine-specific deme-thylase 1 (LSD1) augments the response to inhibitors of the FLT3 kinase in AML. We demonstrate that combined FLT3 and LSD1 inhibition results in synergistic cell death of FLT3-mutant AML cells via proliferative arrest and apoptosis. The drug combination synergistically activates a pro-differentiative epigenetic and transcriptional program while simultaneously suppressing the activity of MYC target genes. High resolution multi-modal epigenetic analyses revealed that combined FLT3 and LSD1 resulted in the suppression of MYC-bound promoters and the activation of PU.1-bound enhanc-ers. Forced expression of MYC partially abrogated the drug effect, and regulon en-richment analysis in primary AML samples nominated STAT5 as a putative regulator of MYC gene expression. STAT5 is highly bound to the MYC blood super-enhancer and inhibition of FLT3 results in a loss of STAT5 binding and a loss of super enhancer acti-vation. Furthermore, knockdown of STAT5 augments LSD1-inhibitor induced cell death. LSD1 inhibition also directly represses MYC target genes which show specific accumulation of the repressive LSD1 substrate H3K9me1. We validated these findings in 67 primary AML samples including 19 FLT3-ITD positive AML samples, with the vast majority demonstrating improved responses with the drug combination. High MYC regulon activity was a predictor of response to the drug combination and RNA-seq on drug treated AML samples revealed suppression of MYC target genes. Finally, single cell ATAC seq on primary AML blasts treated ex-vivo with combined FLT3 and LSD1 inhibition results in a shift from MYC super enhancer-high to a MYC super enhancer-low cell state. Collectively, these studies provide preclinical rationale for the investiga-tion of dual FLT3 and LSD1 inhibition in clinical trial.
2024-03-21 | GSE190785 | GEO
Project description:Disruption of epigenetic regulation is a hallmark of Acute Myeloid Leukemia (AML), but therapeutic interventions are difficult by the interplay of epigenetic mechanisms controlling genomic elements. We hypothesized that concurrent targeting of aberrant promoter and enhancer epigenetic silencing improves efficacy against AML. To test this, we developed an ex vivo culturing system and treated 52 patient-derived AML with low-dose 5-Azacytidine and specific LSD1 inhibitors. Genetic analysis revealed that combination of 5-Azacytidine and LSD1 inhibition was most effective in TET2mut AML. Combination therapy further up-regulated expression of genes associated with both LSD1-bound enhancers and cytosine methylated promoters. Functional validation studies suggest that expression of these genes (e.g. GATA2, GFI1 and DLX2) contribute to drug efficacy. Mechanistically, combination therapy increased enhancer-promoter looping and chromatin-activating marks at the GATA2 locus. This gene induction effect was dampened by CRISPRi of the LSD1-bound enhancer in TET2mut AML. Concordant with TET2mut AML, knockdown of TET2 in human hematopoietic stem and progenitor cells induced loss of enhancer 5-hydroxymethylation and facilitated LSD1-mediated enhancer inactivation. Collectively, our platform revealed increased LSD1-mediated enhancer inactivation after TET2 deficiency that provided a basis for combinatorial epigenetic therapy to activate promoter-enhancer interactions.
2019-10-24 | GSE89521 | GEO
Project description:BRD4 is well known for its role in super-enhancer organization and transcription activation of several prominent oncogenes including c-MYC and BCL2. As such, BRD4 inhibitors have being pursued as promising therapeutics for cancer treatment. However, drug resistance also occurs for BRD4-targeted therapies. Here we report that BRD4, unexpectedly, interacts with the LSD1/NuRD complex and co-localizes with this repressive complex on super-enhancers. Integrative genomic and epigenomic analyses indicate that the BRD4/LSD1/NuRD complex restricts the hyperactivation of a cluster of genes that are functionally linked to drug resistance. Intriguingly, treatment of breast cancer cells with a small molecule inhibitor of BRD4, JQ1, results in no immediate activation of the drug-resistant genes, but long-time treatment or destabilization of LSD1 by PELI1 decommissions the BRD4/LSD1/NuRD complex, leading to resistance to JQ1 as well as to a broad spectrum of therapeutic compounds. Consistently, PELI1 is up-regulated in breast carcinomas, its level is negatively correlated with that of LSD1, and the expression level of the BRD4/LSD1/NuRD complex-restricted genes is strongly correlated with a worse overall survival of breast cancer patients. Together, our study uncovers a functional duality of BRD4 in super-enhancer organization of transcription activation and repression linking to oncogenesis and chemoresistance, respectively, supporting the pursuit of a combined targeting of BRD4 and PELI1 in effective treatment of breast cancer.
2022-02-01 | GSE171908 | GEO